SpO2 has stopped uploading overnight - wifi port blocking?

[kas18]

Every night my fitbit app uploads five health metrics. On 13th June this year, it stopped uploading just the blood oxygen (SpO2) data. (The other four metrics are still being uploaded just fine).

Then I noticed that when I was elsewhere and connected to a different network, the data did get uploaded. So I tried switching from my WiFi to my mobile data connection as a test, and the data was successfully uploaded.

I therefore conclude that the problem is probably with my ISP - perhaps it has started blocking whatever TCP port(s) are being used to upload the SpO2 data. How do I find out what port(s) are being used by the app, so that I can enquire with my ISP about whether they are blocking them? I've tried Googling for the port data, but cannot find anything.

Thanks.

Moderator edit: clarified subject.

[Guy_]

Hi @kas18 - this is strange and most probably not a port issue.

The problem lies elsewhere, possibly in an app version if it's working, try stopping the Fitbit app,  and clear storage cache and restart the phone.

Then now it's working try using WiFi only again and wait an hour after first try and try syncing again.

If that fails try with mobile only. 

Any differences between the two are then more likely VPN, Proxy or such related but it may now be working.

[kas18]

Thanks for your reply. However, the things you suggest were already tried back before I discovered the different behaviour on different networks, and made no difference.

To recap: the fitbit app works perfectly when I'm connected to various other networks (at my daughter's house, when staying in hotels, using my Vodafone mobile data connection). It only fails when using my home ISP's network. I don't use a VPN or any proxy. So it is clear that the problem is not in the fitbit app but in my ISP's network. All I was trying to do was get a feel for what ports the app uses before asking my ISP to investigate.

I have now contacted my ISP and await their response.